There are
“Joyful”, 24 hours,
“Kura-zushi”, 11:00-23:00,
“Saizeriya”, 11:00-26:00,
“Yoro-no-taki”, 16:00-23:00, and
“Apita”, 10:00-21:00
at the yellow box in the following map or “Shokusai Plaza” in Map 3.
International Institute for Advances Studies → Shokusai Plaza
Walk: about 10 minutes
Keihanna Plaza Hotel → Shokusai Plaza
Walk: about 10 minutes
See Bento option at IIAS.